1. Field of the Invention
This invention pertains generally to image coder loop filtering, and more particularly to adaptive loop filtering.
2. Description of Related Art
Image and video signals are sometimes corrupted by Gaussian noise. Wiener filtering can reduce this noise effectively, and is perhaps the best linear restoration filter in the sense of Mean Square Error (MSE). The filter taps of Wiener filters can adapt with local signal and noise statistics.
Images reconstructed using adaptive loop filters have largely relied upon two dimensional Wiener filters. However, the computation of these two dimensional filters by the decoder comprises a significant overhead.
Accordingly, a need exists for an apparatus and method of adaptive filtering which can retain a high perceptual quality with less decoder computation. These needs and others are met within the present invention, which overcomes the deficiencies of previously developed adaptive filtering apparatus and methods.